It was not as if Sindhu did not have her chances. Leading 20-19 in the final game, she squandered a championship point by hitting a return into the net. Zhang capitalised on the opportunity and denied the World number four any further leeway by winning three points in a row to seal the game and contest 22-20.

The first game was a closely contested affair with neither willing to surrender the advantage. They went neck to neck all the way until 15-all before Sindhu let the pressure get to her and conceded three points. Zhang took advantage and rode on the momentum to win 21-18.

Sindhu made a quick recovery and upped her game in the second by covering the court well and minimise the errors to level the scores by winning 21-11 and take the match into the third.

Zhang delivers under pressure

Zhang, who travels without a coach and a sparring partner, said she had nothing to lose and the pressure was more on her rival to deliver. "I think she took more pressure than me," she said.

The victory was doubly sweet for her as she did not win a single match during the Premier Badminton League held in India last month.

"I didn't win any match (in the PBL) and now I have all of it," she exclaimed.

Shi Yuqi delivers on debut

Shi Yuqi, making his maiden appearance in the tournament, made it memorable by clinching the men's singles title and the winner's purse of $26,250. The fourth-seeded Chinese, who had made it to the final of the All England Open Championships, last year downed third seed Chou Tien Chen 21-18, 21-14 in 47 minutes.

It was the 21-year-old's second big victory, following his success in 2016 French Open and will fetch him 9,200 ranking points.

"It was tiring tournament for me as there were long battles and long rallies. It was a tough victory," Yuqi said.

For Tien Chen, it was the second time he failed to cross the final hurdle in the Indian Open. Last year, he had lost to World No1 Viktor Axelsen.

In the women's doubles, third seeds Greysia Polii and Apriyani Rahayu of Indonesia extended their brilliant run in the tournament by winning the final against the second-seeded Thai duo of Jongkolphan Kititharakul and Rawinda Prajongjai 21-18, 21-15.